Science in pastel colored pony land for the Win

I just realized that Twilight and Cadance's ascension is backed up by real world genetics. Ponies are a single species with three subraces that have common ancestors and routinely interbreed-so anywhere you look, you can find examples of even the "purest" of the races to have ancestors of the others in them. Both Twilight and Cadance were born a unicorn and a pegasus, respectively, but in their genetic code they still have DNA coding for the other races-it's just dormant and suppressed in favor of one particular race. However, their ascension unlocked these dormant genes and fascilitated a rapid emergence of all three racial traits on one individual.

I am so glad I took those genetics classes now.

Comments

[Shrink Laureate]

There are instances of individuals switching phenotype - fish that change genders, insects that change caste etc - but only when the species is set up for it. When a species is as clearly caste-delineated as ponies, you need to account for the developmental change as well as the genetic one.

For example, if I were to receive gene therapy that replaced my XY with an XX, my genotype would switch from male to female; but my body would not. I would not instantly get shorter, lose the beard, grow longer hair, gain wider hips etc. These are all things that developed over time. Even the hormones sloshing around my bloodstream wouldn't change until the organs that produce them had. Some of these factors would change sooner than others - those that affect hair growth would change relatively soon, while my skeleton would take years to change, if it ever did at all.

You could flip the caste of a pony by changing their genes within every cell in their body, or more easily by changing the chemical markers that control which genes are expressed. But neither of these would cause the pony to instantly grow wings. Twilight would essentially become an alicorn trapped in a unicorn's body. She would perhaps start to develop uncomfortably strong chest muscles suitable for flight, but no wings to attach them to.

We never saw the origin of Cadance, Celestia or Luna, so we can't say if Twilight's ascension was normal. But it clearly showed an instant change. More critically, rather than growing wings, Twilight is surrounded by magic and appears to be recreated with a different body.